Lead Persulphate, PbS2O8

Lead Persulphate, PbS2O8.(?)3H2O, is formed in solution by adding lead carbonate to persulphuric acid solution, and is obtained on evaporation in vacuo in ill-defined, deliquescent crystals, very soluble in water. From a solution of lead persulphate alkali precipitates lead hydroxide, which is quickly oxidised to the dioxide. It is noteworthy that this salt, PbS2O8, is isomeric with plumbic sulphate, Pb(SO4)2.